AS21 Transponder Fix

Enhance your AS21 transponder experience with this modification fix for Sim Update VIII compatibility. Fixes issues in aircraft like Flight Design CTSL, ICON A5, JMB VL-3, and Zlin Savage Cub, offering improved functionality such as entering full squawk codes and displaying accurate altitude. Easily install and remove from your simulators Community folder for added features like recovering previous squawk codes and automatic timeout for incomplete inputs.